It has been proposed heretofore that nuclear radiation gauges be employed for measuring physical characteristics of materials. One specific example is the use of nuclear radiation moisture gauges to measure hydrogen content and to relate such measurements to moisture. In surveying an area for variations in a physical characteristic such as hydrogen content and moisture, typical processes involve defining a grid to be applied to the area to be surveyed, then moving a gauge from point to point in the grid while measuring the physical characteristic and noting the gauge reading, and thereafter performing necessary calculations and mapping from field notes. One particular application in which such proposals have met with some success is in the surveying of building roof structures as an approach to determining specific areas to be repaired. In such applications, readings are made at a number of predetermined locations distributed in a predetermined array throughout the area of the roof.
While such surveying practices have achieved some acceptance, the practices are subject to operator error and are time-consuming. As a consequence, access to the result of a survey conducted using a nuclear radiation gauge and as described above is delayed.